During the rebuilding of the Royal Dockyard and defences at Sheerness between 1815 and 1827 the Ravelin was constructed in 1816 and is situated between No.1 Bastion and No.2 Bastion. The Ravelin was a triangular outwork with musketry walls 0.74 metres thick, and 2.42 metres high facing Mile Town - it was also used to store gun carriages. At this time a bridge crossed the moat with access onto the Ravelin, when in use as a sally port a bridge connected Mile town to the Ravelin and another bridge connected the Ravelin to Bluetown, forcing all traffic through the defences.
In 1996 Sheppey College was built on the site of the Ravelin, this resulted in a portion of the remaining musket wall being demolished. During the construction of the college an archaeological survey was undertaken and a section of defensive ditch was recorded. In 2001 Sheppey College began an extension, again a survey was undertaken with an archaeological dig in an attempt to record more of the remaining defences. A 29 metre long trench was dug in the hope of providing a detailed section of the defences. A section of ditch, berm (a level space between a parapet or defensive wall and an adjacent steep-walled ditch or moat to reduce soil pressure on the walls of the excavated part to prevent its collapse) and an internal earthen rampart of one side of the Ravelin were discovered. A live sewer pipe was found to run through the ditch and the ditch was filled with contaminated infill that was placed in the 1950’s. The ditch was found to measure more than 12 metres wide and probably 3 metres deep with the inner sides set at an angle of 35 degrees to the horizontal, being lined with ragstone blocks. The earthen rampart that was discovered was to the northwest, this consisted of 1 metre high made ground that ran parallel to the ditch, it was 8 metres wide. Between the rampart and ditch a 1.5 metre wide level berm was found.
The most obvious remaining section to be found today is part of the musketry wall, with the surrounding ditch being infilled in the 1950’s.